1. Field of the Invention
The present invention relates to an integrated digital control system and method for an automotive electrical device, and more particularly, to an integrated digital control system and method for an automotive electrical device in which a vehicle is separated into logic regions, and input and output elements of the separated logic regions are divided to enable digital integration.
2. Description of the Invention
The conventional automotive electrical device is provided in a centralized manner in which there are mounted a switchboard, control switches, etc. with a central instrument panel. Input lines and control lines are wired along and/or within a frame of the vehicle and coupled with the use of connectors. In buses, since the electric devices are provided to the rear of the bus, it is common to require the use of one hundred or more thick wires that are ten meters or more in length. Because such a large number of wires are positioned through the use of connectors within the frame, many electrical wiring problems result, the repair of which is difficult.
Further, since electronic control units of the conventional vehicle are individually mounted on an analog foundation, integrated control is not possible. Also, integration of the electronic control units is not possible because input and output for control of each unit is independentlyprocessed. Accordingly, many electronic control units, and a large number of wires and connectors are needed in the conventional automotive electrical device. The resulting complicated circuit structure makes for the more frequent occurrence of malfunctions and difficult repair.
FIG. 1a shows a schematic view of conventional frame wiring used to connect control switches, an instrument panel, a switchboard and output elements at a front of a bus to sensors. FIG. 1b shows a schematic view of conventional frame wiring used to connect output elements of an engine and sensors, and sensors and output elements provided throughout the remainder of the bus.
The output elements refer to parts that are controlled by electric power of the vehicle. The output elements include lamps, coils, electric motors, and assembly parts. The sensors include an oil meter sensor, a fuel meter sensor, a temperature meter sensor, an internal temperature sensor, etc. That is, the sensors are input elements mounted to the vehicle and which variably perform the display of different states of the vehicle. The sensors also include pulse sensors for generating pulses according to varying states such as an RPM pulse sensor, a KM pulse sensor and an ABS sensor. Additionally included as sensors are all input elements such as a brake light switch, an air deficient switch, a parking light switch, and various switch sensors that are On/Off operated such as a coolant level sensor.
As an example, wiring between a temperature gauge and a temperature sensor will be described. A connector 1 of driver compartment wiring is connected to the temperature gauge of the instrument panel. A connector 2 of the driver compartment wiring is coupled to a connector 5 of a lower wiring of FIG. 1b. The lower wiring circles around a lower portion of the bus leading to the rear of the same. A connector 6 at the rear of the bus is connected to the temperature sensor, thereby interconnecting the temperature gauge and sensor.
As another example, the connection between control switches and interior lights will be described. Interior light switches are connected to a connector 4 of the switchboard as shown in FIG. 1a. After passing through relays and fuses of the switchboard then the driver compartment wiring, connection to an upper wiring is realized through the connector 2 and a connector 3. That is, through the connectors 2 and 3 which provide an outlet for the driver compartment wiring, and connectors 7, 8 and 9, the connection between the control switches and interior lights is completed.
Further, since direct mechanical connections are used by the conventional automotive electrical device, many controllers and parts must be added to enable automatic control of the electrical device.
The most difficult area of control in a control method of the conventional automotive electrical device is that of automatic malfunction detection. This is a result of the sensors and output elements being directly and individually connected. For example, a hydraulic pressure sensor and a hydraulic pressure gauge are connected using many connectors and sections of wiring. If a short is generated in an input wire of the sensor, a short circuit state occurs in all the elements connected to the input wire (the remainder of the wire, hydraulic pressure gauge, etc.). In this case, it is difficult to determine the source of the short circuit (i.e., whether it originates from the wiring itself, connectors, gauge, or other devices used as input by the hydraulic pressure sensor).
Using a charge malfunction as another example, elements that can cause a charge malfunction include a voltage regulator, a generator and a battery. In more detail, a charge malfunction can be caused by problems in the elements just mentioned, corresponding fuses, connections, and indirectly by problems in belts rotating the generator (i.e., an engine pulley belt, an idle pulley belt and a generator pulley belt). Since detection in all these areas is required to enable the determination of the actual cause of malfunction, it is next to impossible to realize automatic detection of a charge malfunction.
The instrument panel displays the driving state of the vehicle and includes a speedometer, an rpm gauge, a temperature gauge, a voltage gauge, various warning lights, etc. The connection of the many sensors directly to the instrumental panel in the driver's compartment further complicates the wiring of the vehicle. Further, since the control switches are operated through direct control of a plurality of devices and controllers, much wiring, many connectors, and many mechanically operated switches are needed.
Lastly, because it is not possible to check the states of the devices and parts, automation of the electrical device is unrealizable.